Operation CHARM: Car repair manuals for everyone.
Home >> Buick >> 1985 >> Skyhawk L4-112 1.8L Turbo VIN J FI >> Repair and Diagnosis >> Relays and Modules >> Relays and Modules - Powertrain Management >> Relays and Modules - Computers and Control Systems >> Engine Control Module >> Service and Repair >> Engine Control Module (ECM) Replacement
Manuals through 2025 now available!

Our trusted friends have launched a new website named LEMON, which has newer manuals. It also contains all the CHARM manuals.

LEMON is the spiritual successor to CHARM, I recommend you try it!

Link: lemon-manuals.la or lemon-manuals.org.ua

(Some people have issue connecting. LEMON is investigating. For now, use Firefox or change your DNS server)

Or, hide this message: temporarily or permanently

Engine Control Module (ECM) Replacement


1. Disconnect battery ground cable.
2. Disconnect two ECM electrical connectors.
3. Remove the ECM mounting hardware.
4. Remove ECM from passenger compartment.
5. Reverse procedure to install.
Replacement ECM is supplied without engine calibration unit (PROM) and, on 1984-85 models equipped with 4-121 overhead valve engine, 1985-86 models equipped with V6 engine and 1986-87 models equipped with 4-121 overhead valve engine and auto. trans., the CALPAK. 1986-87 models equipped with 4-121 overhead valve engine and man. trans. are equipped with a MEM-CAL in place of the PROM. Care must be taken when removing the PROM, CALPAK or MEM-CAL from a defective ECM as they will be used in the replacement ECM.



pro multis · About Operation CHARM